


In my time of sleep

by KafkaTamura



Series: My own AU (sort of) [2]
Category: Undertale (Video Game)
Genre: And I guess, Consensual Somnophilia, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Fluff, Fluff and Smut, Incest, M/M, Manhandling, Plot What Plot/Porn Without Plot, Sibling Incest, Smut, Somnophilia, Soul Sex, also as usual for this ship i will tag this though this is obvious, really this is just an excuse to write some porn don't look for more
Language: English
Status: Completed
Published: 2020-09-06
Updated: 2020-09-06
Packaged: 2021-03-06 20:21:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,084
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26324824
Author URL: https://archiveofourown.org/users/KafkaTamura/pseuds/KafkaTamura
Summary: Sans is tired and falls asleep while they have sex.That's it, that's the whole story!
Relationships: Papyrus/Sans (Undertale)
Series: My own AU (sort of) [2]
Series URL: https://archiveofourown.org/series/1914874
Kudos: 54





	In my time of sleep

**Author's Note:**

> This is sort of a sequel to my fic Beneath the mask, but you don’t have to read it before this one. If I end up writing another fic in this universe (I have some ideas), I will start a series.
> 
> As the tags imply, this is pure smut. There is no story whatsoever here. I just wanted to write Sans and somnophilia together. I mean, he’s by far the best character for this. It’s so easy to picture him falling asleep during sex like he does during battle!
> 
> Also, I know a lot of somnophilia out there tends to be dubious consent at best, but I wanted to do it consensual. So there is actual verbal consent before, and reassurances after, so everything should be good (Papyrus worries a little bit but nothing too dramatic).
> 
> Anyways, I hope this will satisfy some cravings for you people, as it did for me!

Sans came home with his eyes barely opened. He stumbled more than he sat on the couch beside Papyrus with a long and painful sigh. 

“DID YOU HAVE A LONG DAY SANS?”

Sans hummed in response, his body sinking more and more into the couch. Papyrus knew better than to start a conversation, and simply enjoyed the show on TV. Sans would soon fall asleep like this and Papyrus would have to carry him to their bed, but he didn’t mind.

Oh, sure, he had been hoping, all day long, that they would get _busy_ , since it was Friday night. Papyrus didn’t want to admit it, but he was a tiny bit disappointed.

For all the libido Sans had, his body sadly couldn’t always follow. It went without saying that Papyrus would respect that. He was glad Sans got the rest he needed. It was far better than his insomnia from not that long ago.

 _Still_. He had been looking forward to it, all day long, and now, he was the tiniest, itty-bittiest disappointed. 

Papyrus startled right out of his misery when he heard a bang. He immediately sought his brother out with his eyes, his heart beating with worry. Fortunately, even if he was on the floor, Sans seemed fine. Looking tired but determined, he crawled on all fours until he reached Papyrus. Finding purchase on his brother’s knees, Sans opened them up to crash between them.

“SANS? WHAT ARE YOU DOING?” 

Sans managed a wink in his direction, before his hands griped Papyrus’s shorts and started pulling them down. 

Papyrus, a blushing mess now, though very far from resisting, asked his brother, “Y-YOU’RE NOT T-TOO TIRED B-BROTHER?”

Sans smiled, something wicked and oh, so, _sexy_ , before telling him, “for this? never” Then, he manifested his tongue and darted it forward, immediately meeting naked bones. Papyrus whined, still worried about his brother but happy with this new development. 

It didn’t take long for Papyrus’s magic to take form in his usual orange cock. Sans, now with renewed energy, started to lick and then suck like his life depended on it.

Papyrus, moaning, brought a hand to Sans’s skull to pet him, getting a hum as acknowledgement. Sans was a monster of many talent, but you had to admire the things he could do with his tongue. Papyrus sadly didn’t have that kind of skill, although he practised hard whenever he could.

Sans stopped before it became too much. He let his head loll to the side on Papyrus’s thigh, his eyes half-closed and his tongue dripping under him. God was he a sight to behold!

“SHALL WE TAKE THIS TO THE BEDROOM SANS?”

“yesss” Sans agreed. Papyrus closed the television, bent down to pick his brother and stood up. His brother secure in his embrace, Papyrus made his way to the bedroom. On the way, Sans’s expression grew softer, something tender and full of love, in a way he rarely let himself be seen. 

When they reached the bed, Papyrus carefully placed his brother on it and quickly got rid of his own clothes. He could feel Sans’s eyes on him, but he didn’t put much of a show, since he knew they probably didn’t have much time before Sans would fall asleep.

When he was done, he climbed on the bed above Sans and bent down to kiss him. Their teeth clanked before their tongues smoothly intertwined. Papyrus was getting used to this after a couple months, but he still felt so lucky to have this. This thing between them, it was good for both of them. 

Papyrus sadly put an end to the kiss. Sans chased after him, making something inside Papyrus melt, but he didn’t give in. He wanted more! Also, he was the only one naked right now, that wasn’t fair!

“STAY STILL, I WILL UNDRESS YOU NOW!”

Sans’s head fell back and he let himself go completely. Papyrus, with little effort, promptly undressed him. He loved peeling clothes off his brother, it was like opening a very special present! 

Sans chuckled in the face of Papyrus’s enthusiasm, but his laughs turned into a moan when Papyrus stroked his newly exposed spine. Their naked femurs met when Papyrus moved closer.

Papyrus was pleased to notice his brother already had his blue magic manifested between his legs. That would speed things up, since they were on a bit of a schedule. Papyrus didn’t want Sans to fall asleep before they were done!

He kissed him some more, caressing him all over. Sans answered to the kiss but let his brother do everything else. He was usually way more responsive than that, even when he was tired. That was worrying Papyrus a little.

Papyrus broke the kiss once more to ask his brother, “DO YOU REALLY WANT TO CONTINUE? WE CAN GO ON WHEN YOU WAKE UP TOMORROW.”

“no way,” Sans assured him. “i thought about your cock inside me all day long, i cant wait”

Papyrus hadn’t been the only one to look forward to it then. He smiled, but before he could go on and make both their dreams come true, Sans once more talked, “can you turn me on my stomach though?”

Papyrus preferred missionary, but Sans liked to switch it up from time to time. Apparently, Papyrus was too distracting – which was fair, he was Great after all. Being on his stomach helped Sans focus on what he was feeling. He especially needed it when he was feeling overwhelmed or needed comfort.

Although Papyrus didn’t really _get_ it – he always, _always_ wanted to look at his brother, especially during sex – he had no problem granting his wishes.

Therefore, Papyrus turned Sans around. He didn’t do anything to help, not even a little bit, but that was no problem. Sans didn’t weigh a lot to begin with, and Papyrus had always been the strongest between the two. Now that he did it on a daily basis, it was barely worth mentioning. 

When Sans was comfortable, his face hidden in the pillow, his hands gripping the sheets, Papyrus paused a second to admire him. His brother really was beautiful! Papyrus was lucky to get him all to himself.

Papyrus then covered all of his brother with his body. Maybe because he liked sleep so much, Sans loved having something heavy covering him, especially his brother. It always calmed him down, though right now Papyrus could tell from his soulbeat he was more excited than calm.

“Are You Ready?” Papyrus asked in a soft voice, straight into what would have been Sans’s ear if he had one. Sans nodded in the pillow, but stayed silent. His body curved up to meet his though, and when Papyrus started to sink in his heat, Sans pushed back.

Papyrus opted for deep but slow movements, making sure to hit his brother’s sweet spot each and every time. Sans moaned in the pillow and Papyrus grunted with the effort, but they didn’t speak. Sans would sometimes get in a mood during sex and start talking and talking and telling _puns_ and, well, Papyrus knew by now that’s when he _really_ wanted things to get rough. 

A silent Sans usually wanted something a little more tender though, and that suited Papyrus perfectly. 

Papyrus was slowly but surely getting near his finish when Sans turned his head to the right. Sans couldn’t look at him from this angle, but Papyrus could see his eyes getting smaller and smaller. Was he about to fall asleep before they could finish?

“pa-papyrus...”

“YES SANS?” Papyrus asked back, stroking his brother’s hip, moving in a slow steady pace.

“please don’t stop”

Papyrus chuckled, kissed the top of Sans’s head and told him, “I WASN’T PLANNING TO.”

“if i fall asleep, please... don’t stop... i want you to...” Sans stopped to yawn loudly. “huff, go on and finish, ok?”

“WHAT DO YOU MEAN? ARE YOU FALLING ASLEEP?”

Even as he asked that, Papyrus could tell it was happening. He hadn’t been fast enough! His consideration for Sans had backfired!

Sure enough, Sans hid his face in the pillow again and started snoring. Out like a light, just like that. In other circumstances, Papyrus would admire his ability to fall asleep at the drop of a hat, but right now? 

This wasn’t ideal.

He whispered his brother’s name again, but Sans didn’t move at all. He really was gone, probably for the rest of the night too.

Papyrus wondered what to do. Sans’s magic was still there, welcoming, warm and wet. Papyrus didn’t know they could keep their magic manifested even while sleeping!

He started to move slowly, tentatively. Sans was snoring lightly, but otherwise his body didn’t give any signals. Normally, Papyrus could tell by the way Sans reacted if he liked what Papyrus was doing, but now there was no input at all.

A little troubled, but also intrigued, Papyrus gathered his brother in his arms and moved them to their side. Sans didn’t stir at all. Papyrus could see his face now, and it was very peaceful. Calm.

Papyrus knew that having sex with someone when they were asleep was a very bad thing to do, but Sans had told him not to stop, right? Sans wouldn’t have told him that if he didn’t want to, but had he been in the right mind to make that choice? 

Even while he wondered, Papyrus started moving again. Sans usually ran hot when they were doing it, but he was even warmer than usual. His body, completely lax in Papyrus’s arms, was so warm, heavier than normal, and, somehow, _welcoming_.

That’s when Papyrus realized he wouldn’t stop. This was weird, and maybe not completely okay, but it felt also really, _really_ good. 

Papyrus moved one hand to Sans’s hip and started moving more frankly, in search of a new rhythm. Sans probably wouldn’t wake up no matter what he did, but he still didn’t want to go too fast just in case. 

They had tried some _things_ , but overall sex between them stayed pretty vanilla. Papyrus wouldn’t complain, at all, but he had to admit trying something new was also exhilarating. He got to know a new side to his brother.

That’s why he wanted to enjoy this, take his time, and make sure Sans wouldn’t wake up. 

Papyrus kept his gaze on his brother’s face, trying to read signals that simply weren’t there. He was breathing deeply now, not snoring anymore, until he started letting out cute little sighs. 

His tongue was long gone, sadly, but Papyrus brought his hand to his rib cage, feeling the thumping of his soul behind the bones. It was steady and slow, unlike every time they were having sex. Papyrus quickly found his rhythm in the soul’s beats and closed his eyes.

This was comforting, even _relaxing_. It was weird for sex to feel this way, but Papyrus enjoyed it. He so rarely got to relax. Of course, leave it up to his brother to show him how to relax during sex of all things!

Papyrus let out a chuckle, trying hard to stay as silent as possible. He was so attuned to Sans’s breathing that he immediately stopped moving when Sans gasped. Then, barely above a whisper, Sans call out his name, “p-papyrus”

Papyrus held his breath. Was Sans waking up? Papyrus got nervous again, wondering if what he was doing was really correct. It felt good, but, then again, a lot of bad things did.

Sans’s expression changed a bit. He clenched his teeth, before letting out another sigh. Could it be? Was he calling his name because he was dreaming about him?

Papyrus’s chest and whole face felt hot. Somehow, the idea of Sans dreaming about him felt incredibly lewd and _hot_. Papyrus moved a little, as if to gauge his reaction, and Sans let out a little moan that turned into the first half of his name.

Papyrus started to move with a new rhythm now, faster than before, and Sans called his name another time, along with pleads for him to go faster, deeper. He checked regularly, but he was still talking in his sleep. 

There was no doubt now that he was dreaming about them having sex. Why was this so unbearably hot? 

Papyrus was getting closer and closer to his release now. He had lasted a lot longer than usual, between his worrying and making sure not to wake Sans, but he was getting there. Sans calling his name so lewdly in his sleep did help a lot.

His hand was still griping Sans’s thorax after all this time, but his grip faltered. In an attempt to gripe it back, the tip of his finger grazed Sans’s soul. That. Felt. _Amazing_.

Papyrus let go and moved his fingers along Sans’s spine, wondering if he was crossing another line. Sans had told him time and again that he could always, without exception, touch his soul, that he trusted him with it and had no secrets from him anymore. Papyrus always made sure to ask before he did, but he was too curious this time.

He had to know what Sans was feeling. He just _had_ to know!

When he reached the soul, he carefully cupped it in his hand, stroking it with his thumb. Closing his eyes again, Papyrus tried to identify all the emotions in Sans’s soul. Sadly, he couldn’t see the dream, but he could tell how it made Sans feel. 

It wasn’t the first time they shared their souls while they had sex. Papyrus was used to the all encompassing love and the bottomless desire, but he was taken aback by how calm Sans felt. How comfortable, and happy, and _safe_ , he was.

Sans was always a bit guarded. They were working on it, but many genocide routes and all the traumas he’d been through had made him alert and stressed on a regular basis. It was rare enough to see him completely unwind, but Papyrus had honestly, in all their time together, never felt Sans so _unburdened_.

To think, sleep used to be one of those things Sans dreaded the most. Because of his nightmares, and insomnia, for a lazy monster, he had something of a love-hate relationship with sleep. He had learned to love it again since they were sleeping in the same bed and the nightmares were now far in between, though not completely gone.

Papyrus felt a tear fall down. This was a reminder that Sans never felt completely safe and okay when he was awake, and no amount of Papyrus helping could cure that. 

At the same time, Papyrus was happy to finally know this side of Sans. His magic was so amazing, blue and cool and strong. He had so much more magic than Papyrus, though he rarely used it. Papyrus stroked the soul once more, drying his tear and moving again in his brother’s sweet, beautiful magic.

This truly felt like coming home.

Soon though, the pleasure, from him and Sans, grew and grew until it culminated. Papyrus came without a sound, but Sans moaned one last time. 

He held the soul in his hand long after their magic evaporated. Papyrus soon fell asleep, only then letting go of his brother’s soul.

When Papyrus woke up next morning, Sans was looking at him with an adoring smile. Sans kissed his cheekbone before telling him, “thanks for last night paps, i had an amazing dream”

“I DIDN’T DO ANYTHING BAD DID I? SHOULD I HAVE WOKEN YOU UP OR STOPPED RIGHT AWAY? I –”

“shh,” Sans shushed him with a finger on his teeth and a smile, “i asked for it and i wanted it, trust me. though, that wasn’t fair, springing it on you like that. we should have discussed it before. so, euhm, i’m sorry.”

Papyrus relaxed. Thank god it was okay. He wasn’t sure what he would have done if Sans had resented him. 

“DON’T WORRY BROTHER, AS LONG AS YOU ARE OKAY THEN I AM TOO!”

Sans looked relieved. He was right, they should have talked before, but at least nobody had been hurt.

“truth is,” Sans moved on top of Papyrus, sinking easily into his embrace, “i’ve been wanting that for a while now. i mean, top three things i love the most, you, sex, and sleep, at the same time? i knew it would be amazing.”

Papyrus turned them on their side to have a better view of Sans’s expression, keeping him in his arms though. “BUT YOU WERE ASLEEP THE WHOLE TIME SANS, HOW CAN YOU TELL?”

Sans winked at him, mischievous, “like i said, i had a good dream. what about you paps? did you like it?”

Papyrus admitted, feeling his cheeks grow a little warmer, “I SURPRISINGLY ENJOYED IT.”

Sans hummed too. Papyrus could tell he was getting in a teasing mood. To avoid a joke, or God forbid a _pun_ , Papyrus beat him to the punch and explained, “YOU WERE VERY WARM AND PEACEFUL, AND KNOWING YOU WERE DREAMING ABOUT ME WAS VERY AMAZING! I COULD FEEL YOUR SOUL BEATING, SLOW AND STEADY, AND IT WAS... COMFORTING? YOU ALSO LET OUT SOME CUTE LITTLE NOISES.”

It was time for Sans to blush now. Papyrus cupped his face to tell him, “I WANT TO DO IT AGAIN, BUT ONLY IF YOU WANT IT TOO.”

Sans looked into his eyes for a couple seconds, then he suggested, “what about, if i’m naked and i didn’t say no before, that means you can do it? if i don’t want to i’ll make sure to wear something or tell you.”

There was always the chance Sans could forget to tell him, but, for now, Papyrus didn’t object. He had no plan to do it without his explicit consent anyway. They could discuss it at length some other time, since now it was pretty obvious Sans wouldn’t fall asleep in the foreseeable future.

Papyrus moved to cover his brother like a blanket. Sans sighed contentedly. They had nowhere to be right now and could simply enjoy each other in peace.

“say, paps?” Papyrus hummed, letting his brother talk some more. “can we try my fourth favorite thing next time?”

“PLEASE DON’T SAY KETCHUP!” Papyrus would soon regret those words.

“huh” Sans said pensively, “i was gonna say ‘food’, but it seems like you got the better idea.”

“REALLY SANS?”

“hey, youre the one who said it”

Papyrus sighed. What he wouldn’t do for his brother!

**Author's Note:**

> An idea for next time? Maybe, maybe not, I won’t promise anything. Just wanted to end it on a bit of a silly note since this is them after all.
> 
> Hope you had a good read, and, as usual, please tell me if I forgot a tag!


End file.
